The invention relates to a pile repair jacket form being useful in repairing bridge, pier or walkway supports that are submerged in a body of water. Walkways such as piers or boardwalks are supported over a body of water by way of piles that have been driven into the bottom of the body of water below the mud line. Such piles can consist of concrete, timber and steel. It is obvious that the concrete, timber and steel piles are subject to corrosion or deterioration because of being permanently located in a water environment. Concrete piles are subject to corrosion, especially if the steel re-bars located therein are subject to rusting if they are located too close to the outer surface of the concrete pile or are exposed altogether. The timber piles are always pressure treated against corrosion or deterioration but the time span of their useful life is substantially shortened when the timber piles are located in a body of water. Steel piles are water proofed prior to their installation but over a period of time the water proofing is not durable or protective enough to protect the steel from corroding.
Most of the damage in all of the above supporting piles occurs at the water line because of the wave action. This wave action is further aggravated by the tides which are prevalent at most installations. In many installations, the high tide covers a greater height of the pile, while at a low tide, a greater length of the pile is exposed to the environment. Therefore, the piles undergo drying and wetting cycles which tend to eat away at the pilings, especially the wooden piles, thus weakening the piles mostly at their mid sections of their total length. Also, water insects like marine borers tend to accelerate the above noted deterioration and are the leading cause of timber pile deterioration.
Many devices have been used to repair the above noted damages short of replacing the pilings altogether. This tends to substantially increase the cost of such an installation.
The DENSO(trademark) North America Corp. teaches the use of fiber form jackets that are placed over the whole length of the pile to be repaired or over the damage at the tidal zone. The jacket is made of fiber glass and therefore has some flexure in the material, especially over greater lengths. Because of its ability to flex, the jackets can be installed at the desired location without having to disassemble the superstructure above the piles. Once in place, the jackets at their longitudinal open edges have a tongue and groove arrangement to close and seal the longitudinal edges. Bandings are placed around the jacket at about every 12xe2x80x3. Also standoffs between the pile and the interior surface of the jacket should be used to increase its stability. The use of fiberglass material is very expensive.
Another suggested use is demonstrated by the above noted corporation and that is the use of a fabric form jackets. The fabric form jacket is made of 100% continuous multifilament NYLON fibers and is placed around the damaged area of the pile and the top and the bottom is then closed against the pile by banding. A longitudinal zipper is then closed to complete a cylindrical enclosure. A disadvantage with this kind of an arrangement is that the cylindrical fabric form does not have a form stability in that when the concrete fill is inserted therein, it has a tendency to collect more concrete in the bottom of the cylinder and less at the top, whereby a pear-shaped form is assumed. Therefore, more concrete has to be used than is necessary. Hydraulic concrete is quite expensive. Also, the fabric form pile jacket itself is quite expensive.
A similar jacket system is disclosed by the ROCKWATER Corp. in Farmingdale, N.Y. They disclose fiberglass reinforced pile jackets under the name of ROCKFORM(trademark) F and a nylon Pile Jacket under the name of ROCKFORM(trademark) N. As a matter of fact, there is an illustration in their brochure showing the nylon jacket installed on a pile after having been filled with concrete. This illustration clearly demonstrates the disadvantage of this type of a repair wherein more of the concrete is located in the bottom of the bag instead of being equally distributed throughout the length of the bag, as was enumerated above already
Another form jacket is disclosed by the DESLAURIERS, Inc. company. The disclosed jacket consists of two halves that have to be bolted together at their respective flanges and therefore can be installed around existing piles without having to disturb the decking which is supported by the same. However, the assembly underwater is quite cumbersome, expensive and time consuming.
According to the invention, applicant is using a high density polyethylene HDPE pipe, which pipe has a smooth interior wall and an annular corrugated exterior for strength. This pipe is manufactured by the Advanced Drainage Systems, Inc. of Columbus, Ohio. High Density Polyethylene is an extremely tough material that can easily withstand the normal impacts involved in shipping and installation. The proposed applications for this pipe have been specified for culverts, cross drains, storm sewers, land fills and other public and private constructions. There is no proposal to use these pipes for repairing pile supports above water or below.
The pipe, as is, could be used for that purpose but only after the decking, which is supported by the pile, has been removed, and then the pipe could be slipped over and along the pile. However, this pipe cannot be used as a jacket in sections above and below water without first removing the decking or superstructure. In the inventive concept, the pipe has been modified for this purpose by cutting through the pipe longitudinally first. This cutting alone will not suffice because the annular corrugations prevent the pipe at its longitudinal cut to be opened to such an extent and size so that the jacket can easily be slipped around a damaged pile. The corrugations are of such a size and strength so as to not allow any such movement. To accommodate a proper opening, the casing or jacket has been cut in a V-shape and only through the corrugations and opposite the longitudinal cut but not into the wall itself that supports the corrugations and forms the interior smooth surface, thereby creating a live hinge. The HDPE material is flexible enough to allow repeated openings and closings of the jacket along its live hinge without breaking or separating. The corrugated pipe is readily available in diameters from 4 inches to 48 inches and therefore lends itself to many applications including in square concrete pile applications. The pipe also is available in various lengths which enhances the installation possibilities under water. If various lengths have to be assembled, the various sections can be supplied with bell- and spigot ends that fit well within each other including various seals between the sections.